Indexable ceramic cutting inserts for detachable mounting on a tool holder, are generally made of alumina, alumina/zirconia, silicon nitride or other ceramic and are formed by hot pressing or cold pressing and sintering techniques.
In the past, ceramic type cutting inserts for metal cutting typically used negative type geometries to form a strong cutting edge. When cutting a particular material, the formation of an appropriate chip under various feed and speed conditions would not be optimized.
U.S. Pat. No. 4,616,963 to Habert describes a ceramic cutting tip having an encircling bevel with an adjacent channel. The channel has a cross section in the form of a segment of a circle with a chord at an angle of from 15 to 35 degrees with respect to the top surface.